Sumayya Saied

Heavy metal toxicity levels in the coastal sediments of the Arabian Sea along the urban Karachi (Pakistan) region

Heavy metals are stable and persistent environmental contam-inants since they cannot be degraded or destroyed. Therefore, theytend to accumulate in the soils and sediments. Excessive levels ofmetals in sediments affect marine biota and pose a risk to humanhealth through the consumption of seafood (Adams et al., 1992;Rowlatt and Lovell, 1994; Mucha et al., 2003; Feng et al., 2004;Zhang et al., 2007). The main anthropogenic sources of heavy met-als are various industrial point sources, including present and for-mer mining activities, foundries and smelters, and diffuse sourcessuch as piping, combustion by-products, traffic, etc. (NRC, 1989;Bryan and Langston, 1992; Long, 2000; Pekey, 2006; Hyun et al.,2007). Relatively volatile heavy metals and those that become at-tached to air-borne particles can be widely dispersed on very largescales. Heavy metals in aqueous and sedimentary transport (e.g.,river run-off) enter the normal coastal biogeochemical cycle andare largely retained within near-shore and shelf regions in propor-tion to geochemical controls (McAlister et al., 2005; Chaparro et al.,2005). Sediment analyses play a crucial role in assessing the degreeof heavy metal pollution and the resulting health risk associatedwith the food chain.Karachi is situated at the southern most part of Pakistan alongthe Arabian Sea and it is the largest business hub and the mostheavily populated urban centre in the vicinity. The coastal zoneof Karachi is about 167 km long. The estimated population of Kar-achiis morethan15 million.The rapidindustrializationandurban-ization of the city has altered the quality of the environment andcreated ecological disturbances and associated problems for the lo-cal community. Pollution in the Karachi coastal region is mainlyattributed to the Lyari and Malir rivers, which are served by vari-ous channels of untreated domestic and industrial waste, carryingmore than 300 million gallons per day (MGD) (1,125,000 m

Oxindole Derivatives: Synthesis and Antiglycation Activity

Oxindole derivatives 3-25 have been synthesized from commercially available oxindole by refluxing with different aromatic aldehydes in good yields. Their in vitro antiglycation potential has been evaluated. They showed a varying degree of antiglycation activity with IC50 values ranging between 150.4 - 856.7 µM. 3-[(3-Chlorophenyl)methylidene]- 1,3-dihydro-2H-indol-2-one (IC50 = 150.4 ± 2.5 µM) is the most active compound among the series, better than the standard rutin with an IC50 value 294.5 ± 1.50 µM. The structures of the compounds were elucidated by 1H-NMR and mass spectroscopy and elemental analysis. A limited structure-activity relationship has been developed.

A steroidal glycoside from Clerodendron inerme

Abstract A steroidal glycoside, 3- O -β- d -galactopyranosyl-(24β)-ethylcolesta-5.22.25-trien ( 1 ), was isolated from Clerodendron inerme . Clerosterol and glutinol were also isolated from this plant.

PEG–lipid telechelics incorporating fatty acids from canola oil: synthesis, characterization and solution self-assembly

The synthesis of amphiphilic, ABA type, novel PEG–lipid telechelics and their solution self-assembly have been reported. Natural fatty acids were functionalized with a propargyl group. Poly(ethylene glycol) (PEG) and glycerol ethoxylate (GE) were functionalized with terminal azides. The functionalized PEG, GE and fatty acids were then conjugated using click chemistry. Characterization of these conjugates has been carried out with the help of 1HNMR, FTIR, and GPC and further evaluated for their solution self-assembly. The particle size and morphology of nanoparticles were observed with transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. The results prove the high conjugation efficiency and self-assembly of telechelics into nanoparticles of different average sizes in solution. This study highlights that these novel telechelic nanoparticles may serve as a potential drug carriers. The strategy presented herein can potentially be extended to the preparation of natural fatty acid functionalized assemblies with other hydrophilic polymers for therapeutic applications.

Evaluation of the thiazole Schiff bases as \(\upbeta \)-glucuronidase inhibitors and their in silico studies

Twenty eight (28) derivatives 2–29 were synthesized and four analogs were found to exhibit single-digit

Xanthine oxidase inhibitory activity of nicotino/isonicotinohydrazides: A systematic approach from in vitro, in silico to in vivo studies

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Persistence and Degradation of Imidacloprid in Wheat Crop

IC50 values as